Shaving implement



Patented May 7., v1940 PATENT OFFICE o `SHAVING IMPLEMENT Joseph Muros, Cambridge, Mass., assigner to Gillette Safety Razor Company, Boston, Mass., a corporation of Delaware Application March 12, 1936, Serial No. 68,491

9 Claims.

This invention relates to implements of the vibratory shear type employed for shaving without use of lather. ,Heretofore such implements have not been entirely satifactory to many users because they tend-to leave a noticeable stubble on the face andtheir operation does not compare favorably in this respect to the results secured by the use of a razor. j

Objects of the present invention are to provide a closer cutting implement than has been available heretofore, and in general, to improve the construction and convenience of manipulation and safety of implements of this class. An important feature of the invention consists in a shear plate having a series of projections in each of which is incorporated a guard fin and a thin edged lifting blade. I have discovered that by providing a series of thin, round-end fins disposed substantially perpendicular-to the shearing plane I am able to control the skin being shaved, keeping -it under tension between the fins so that the effective edges of the shearingv teeth maybe brought to bear directly 'on the skin withoutdangeref cutting. The length of the stubble is thus reduced to a minimum. Moreover, the lifting blades are effectiveto lift and straighten individual hairs, which may have been vlaid over upon the skin, and to present-them to the shearing teeth in upright position so that they may be cut to the best advantage. vlin the embodiment 'of the invention herein shown, each guard iin is provided with lifting blades on both sides thereof and the advance edges of the blades are shaped not only to lift the Ahairs to be operated on as above explained but to direct them into the opening of the shear teeth.

Other features of. the invention relate to certain proportions`and relative dimensions of the guard ns, lifting blades and c'o-operating shear teeth which I have discovered are of value in contributing toA a close cutting operation of the implement. For example, it is advantageous to limit the opening between the lifting blades to .008 of an inch, a width less than the usual -combined width of two hairs, in order that when a lhair has once reached this position it may not have an opportunity to become bent over but must be cut in upright position and 'with a substantially square cut. The toothed shear plates taper forwardly to a vertex and I have'found that it is advantageous to limit the depth of the teeth to about .020 of an inch because a hair sheared even in the innermost position in such a tooth will leave no appreciable stubble. It is also important that the spaces between theteeth of the movable plate be greater than the spaces between the teeth of the stationary plate in order'tol insure the complete cutting ofevery hair introduced into the tooth space and to eliminate all tendency to kick out. While these dimensions and propor- 6 tions may be varied, those suggested result in the best and most satisfactory operation of the device e and materially contribute to the desired results.

Another feature of the invention consists in co-operating shear plates both tapering to a com- 10 mon vertex contained wholly within, one of the plates. Preferably, moreover, the two shear plates are ground together so as to present a single inclined skin-engaging surface of substantial area which includes their common line of l5 contact. This again is a feature which contributes to the -production of a close cutting implement. I

These and other features of the invention will be best'understood and appreciated from the fol- 20 lowing description of a preferred embodiment thereof, selected for purposes of illustration and shown in the accompanying large scale drawing in which--` Fig. 1 is a fragmentary plan view of the imple 25 ment as seen from above;

Fig. 2 is a vview of the implementI in cross-section;

Fig. 3 is a fragmentary plan view of the implement as seen from below;

Fig. A4 is a fragmentary view in perspective and on a greatly enlarged scale of the o o-operating shear plate; and o Fig. 5 is a corresponding view in cross-section, suggesting a slight modification in the relation 35 of the shear plates.

The implement comprises arr elongated casing which serves also as a handle and' from the forward end of which project the two shear plates I0 and I4. 'I'he upper end only of the casing is 40 shown in Fig. 2 and Within the .body thereof is houseda small electric motor which is connected through an actuating lever I1 to the movable shear plate I4. By these means the movable shear plate is maintained in a state of rapid vibra- 45 -V tion when the implement is in use.

The stationary shear plate I0 is provided in its inner face with a longitudinal rib I I, which is defined by two recessed areas inthe face of the plate. Its upper edge is beveled and serrated to 50 form a series of thin spaced guard fins I2. On both sides of each guard fin is formed a curved lifting blade I3. 'I'Ihe ends of the ,guard fins I2 are rounded so that they engage the face of the user smoothly, stretching theskin in the intermediate spaces between them and holding it under sumcientftension to prevent it from entering the space between the shearing teeth of the two plates. The `lifting blades I3 lie at on the skin and do not extend to the vouter ends of the guard 'iins l2 but terminate in a blade-edge located about .03" behind the front or outer edge of the guard ns. The lifting blades are curved sharp- -ly upwardly and rearwardly in a concave curve. Their principal function is to engage and lift any hairs which do not stand upright upon the lface of the user. The outer ends of the lifting blades are rounded so that the blades also function to direct these hairs into the space between them. Ina preferred embodiment of the invention this space is made .008", that is to say, wide enough to admit only a single hair at a time and lto hold it against being bent over at an acute angle. The under face of each lifting blade I3 is attened and ground to actY as a shear sur- -iace in (so-operation with the movable teeth of the implement.

The movable plate l is provided with square teeth I5 in its front edge. Its inner surface bears `against the surface of the stationary plate I0, de- -ilning therewith the shearing plane, as shown in Fig. 2, and the root line of the teeth I5 coincides substantially with the root line of the spaces between the lifting blades I3. The movable plate is provided on its inner face with a channel of rectangular cross-section which ts over the rib -II and thus the plate Ill is guided accurately in its reciprocation with respect to the stationary plate Il). In a preferred embodiment of the invention the movable plate I4 is bevelled at an angle of 16, the space between adjacent teeth is .016 of an inch and the length or depth of the teeth is .020 of an inch. While these exact dimensions are not essential they are desirable since they bring the cutting area of the implement into a zone where the hair will be cut off with a minimum length of stubble. As shownin Fig. 2, the stationary plate is clamped in position in the casing 20 by means of a knurled-head bolt 22 which passes through a nut 2i locating Within the end of the casing and an oppositely disposed filler piece 23. The latter'is cut away to permit the passage of the actuating lever II and bears upon the opposite side of the stationary plate I0 from the retaining bolt 22. The vibratory plate I4 is provided with a recess I6 for the rounded head of the operating 4lever I1 and this plate is held at all times firmly against the stationary plate I0 by means of a sti spring 24 set in the filler piece 23.

As shown in Fig. 2, the ends of the shear plates I0 and I 4 are ground to a common taper whose vertex is lformed in the rounded ends of the guard ns I2. The skin-engaging faceof the implement is consequently formed partly by thev iins I2 and the lifting blades I3 of the stationary lplate I0 and partly by the beveled face of the vibratory plate I4. This contact surface of the implement is a flush surface formed by grinding the assembled plates and it makes an ac ute angle with the shearing plane as determined by the engaged faces of the two plates. This undershot construction contributes still further to the production of a close cutting implement.

In operation the implement is advanced upon the face of the user with the lower plate I4 next to the surface to be shaved in a state of rapid vibration. 'I'he fins I2 and lifting blades I3 cooperate to tension the skin and to lift and deilect the hairs into the spwe between adjacent liftmovable 4shear plate.

of the implement, to guide the hairs into the recesses between the vibrating teeth I5 of the plate is thereupon effective to shear the hairs against the under-shearing surfaces of the stationary plate. In an implement constructed in accordance with the dimensions herein shownv the maximum length of stubble will be less than 1002", this corresponding to the innermost position between the teeth I6 which any single hair can reach in an upright position. On the other hand, the majority of hairs are cut before they reach the innermost end of the teeth I5 and accordingly leave no discernible stubble. l

I wish to note again as a feature of practicable importance the fact that the lifting blades are divergently curved at their outer ends and then merge into straight shearing edges immediately behind their divergent portions. These divergent edges are effective in directing the hairs into the shearing zone and then the straight edges are utilized immediately to shearl them very close to the skin of the user.

In Fig. 5 is shown a modication of the two shear plates in respect to their contact surface. Instead of being ush as shown in Fig. 2, the

surface of the vibratory plate I4 in this case may be slightly offset with respect to the contact surface of the stationary shear plate I0.

Having thus described my invention what l,

The movement of this one plate including a rounded guard iin and a each including an upright fin having a rounded end and a curved shoulder at one side of 'the iin providing a lifting surface and a shearing surface converging to a thin edge located in advance of the shearing line.

5. A shaving implement comprising co-operating relatively movable plates provided with overlapping shearing projections, the projections of one plate being shorter than those of. the other plate and the longer projections each including a round-end guard iin arranged between two shoulders, each of the shoulders having' a flat shearing face and a curved liftingY face, said faces converging to a thin edge in advance of the shorter set of projections.

6. A shaving implement comprising a reciproeating plate having spaced teeth in one edge, and a stationary superposed plate having correspondingly spaced teeth overlapping those of the reciprocating plate and each including a centrally disposed guard n, a thin-edged lifting blade 'disposed on each face o'f the nn vand inclined 75 away therefrom at its forward edge and an oyerhangin shear face.

'1. A shaving implement' comprising a toothed cutter, andl a cooperating plate having spaced projections in its edge, each projection carrying a shearing surface, a blunt nosed n and a litting blade, the ilnsv being spaced apart substantially i024".

8. A shaving implement comprising a stationary plate havingl a'series of perpendicular guard tins flanked by at lifting blades with edges which shoulders.

converge into spaced hair-receiving spaces bounded by side shearing edges, and a plate havingshear teeth movable across said hair-receiving spaces.

9. shaving implement comprising cooperating plates having openings forming superposed shear teeth.y the openings in one of said plates being bounded `at opposite edges by curved lifting JOSEPH Monos. 1u 

